Black Won't Print On Edible Printer

I'm sure this has been addressed a million times but now that I need the info I can't find it. I have a Canon 3500 printer and KopyKake ink and the black ink won't print. I bought everything new about a month ago and have used it about once a week since. Does anyone know how to fix it or can you point me to a thread where it's already been answered? Thanks.